The debate about which natural refrigerant delivers the greatest energy efficiencies was addressed in a recent European food retail study.
For more than a decade, European food retailers have been among the first adopters of natural refrigerants, particularly CO2 and the hydrocarbon propane (R-290). As refrigeration typically accounts for 35–50 percent of a supermarket’s total energy use, retailers have long sought energy-efficient refrigeration strategies. Recently, Emerson conducted a research project, in conjunction with German research institute ILK Dresden, to compare the relative energy efficiencies of CO2 and R-290 systems used in European discount food retail stores.
The study took place from 2015–2016 and focused on the most common size profile for European supermarkets, which typically house an average of 10 display cases and cover an area of approximately 1,000 m2 (11,000 square feet). The analysis compared integral R-290 systems — medium -temp self-contained display cases on a shared condensing water loop that transfers heat outside a store — to CO2 transcritical remote rack setups.
The study found that those opting for integral R-290 systems could potentially achieve up to €51,000 savings per store on maintenance, energy consumption and refurbishment. Extrapolating this across a network of 10,000 stores over a 10-year period, a retailer could potentially realize a total savings of up to €510,000,000, the U.S. equivalent of $590,000,000.
